The Capitol Extension connects the Capitol and Herschler Building underground. The roof of the existing tunnel had significant deterioration, replacing it created the opportunity to light the space with skylights and provide views of the Capitol dome above.

Demolition is complete in the Capitol Extension, which connects the Capitol to the Herschler buildings underground. Concrete forms are now being erected to pour the walls for the six new large public meeting rooms being constructed in the Capitol Extension. Demolition is also complete in the Herschler West Building and construction is progressing. The Herschler East Building opened to the public in May.

The Wyoming Capitol Square Project centers on the restoration of the Capitol, which is a National Historic Landmark, and addressing life safety and building systems deficiencies. The addition of new mechanical, electrical, and plumbing systems, new elevators, and more restrooms has reduced office space in the Capitol. The Herschler buildings and the Capitol Extension are being renovated and expanded to accommodate these displaced space needs.